: i always thought there was a certain beauty to the theory that the
: forerunners created the flood. gravemind being a monument to the sins of
: the father would make more sense that way. who knows, nobody ever said the
: forerunner WEREN'T extragalactic in origin. unless they did, in which case
: i'm dead wrong about everything.

It's heavily implied in the Bestiary that the Forerunners were not Transgalactic, as that would have put them on Tier 0 with the Precursors. They were Tier 1.